The invention relates to a tractor-trailer with two component vehicles, specifically a tractor and a trailer, with a trailer coupling to create an articulated push/pull connection between the two component vehicles and with a supply coupling between the two component vehicles, wherein the supply coupling comprises a tractor-side coupling half (hereinafter sometimes called "tractor coupling half") and a trailer-side coupling half (hereinafter sometimes called "trailer coupling half"), which can be coupled together by bringing them together along a predefined coupling axis, wherein one of the coupling halves is connected to the supply unit of the associated first component vehicle through a flexible supply line, and when coupled to the other coupling half is movable relative to the first component vehicle in such a way that relative motions of the two component vehicles are essentially unhindered.
A supply coupling here is understood to mean a coupling between two sections of a line that is intended and suitable for supplying the trailer, from a supply unit in the tractor, with electric current and/or control commands and/or compressed air and/or hydraulic fluid for a wide variety of functions such as lighting, braking, dump body actuation and the like. It is certainly possible in this context to provide a plurality of supply lines and a corresponding number of supply couplings for the various feeds. However, for reasons of simplified handling, it is preferred to combine as many supply lines as possible in one cable harness or hose harness in order to make all necessary supply lines functional by connecting a single or a few supply couplings.
In conventional tractor-trailer rigs, the supply couplings are connected by hand. To do so, it is necessary for the operator to move from the driver's seat to the region of the front wall of the trailer and connect the two coupling halves there.
EP 0 539 675 A1 discloses a tractor-trailer in which the supply coupling is designed and arranged such that the two coupling halves are forced to engage with one another when the tractor approaches the trailer in order to establish the push/pull connection between the two component vehicles. To this end, the tractor coupling half on the tractor is held in a mount in a capture-ready position. Attached to the trailer is a toothed rack which engages with the tractor coupling half when the tractor approaches the trailer, i.e., catches the coupling half and extracts it from the mount. The tractor coupling half is subsequently moved along the toothed rack to the trailer coupling half and coupled thereto by means of a motor.
In the tractor-trailer known from EP 0 539 675 A1, the tractor must approach the trailer with a predetermined relative orientation thereto that is within quite tight limits in order to ensure proper capture of the tractor coupling half by the toothed rack. In particular, the tractor and trailer must have zero or only a very small relative tilt about the lateral axis, such as can occur when the trailer stands on a level stretch but the tractor is located on a rising or descending ramp. With the known tractor-trailer, it can occur in this case that the tractor coupling half is not properly captured by the toothed rack and falls down.